Before Mr Macron settled into Fort de Brégançon, the Mediterranean presidential retreat, camera footage emerged of his private bodyguard impersonating a police officer and punching protesters during the May Day riots.

His government’s strong parliamentary majority helped it survive two votes of no confidence over its handling of the scandal in July. But the votes for the first time united opposition leftwing and rightwing parties against Mr Macron.

By the time Mr Hulot resigned on Tuesday, criticising “an accumulation of disappointments” during his time in office and saying Mr Macron’s government had made only “small steps” in its much-vaunted green agenda, the so-called Benalla affair had helped bring Mr Macron’s approval ratings down for the fourth consecutive month, to a record low of 34 per cent.

“Hulot’s resignation is very bad news for Macron because he’s already facing a difficult rentrée,” said Professor Bruno Cautrès, a political analyst at Sciences Po, referring to the return to work after France’s long summer holidays. “The budget is looking more and more complicated, and the polls show that the Benalla affair has hurt his popularity. Hulot’s departure adds another difficult element.”

According to a poll conducted on Tuesday by Odoxa-Dentsu Consulting for France Info and Le Figaro, the majority of French people (55 per cent) regret Mr Hulot’s resignation, and 65 per cent of respondents believe that it is “bad news for the government”. Jean-Luc Mélenchon, leader of the far-left Unbowed party, said in a tweet on Tuesday that it proved that “Macronism is starting to decompose”. Mr Macron, who came to power on a pro-business reform program that he argued would boost growth and create jobs, notched up a number of milestones in his first year as president, overhauling France’s sclerotic labour laws, reforming the state-owned railway operator SNCF and slashing taxes.

But while this has changed the mood at home and France’s image abroad, it has yet to be reflected in the numbers. Unemployment, at just over 9 per cent, has dropped by only 0.3 percentage points during Mr Macron’s presidency. Prime minister Edouard Philippe said on Sunday that the 2019 budget, which will be unveiled next month, will be based on a growth forecast of 1.7 per cent, instead of the 1.9 per cent forecast in April.

Mr Macron is facing many more difficult issues than Mr Hulot’s resignation, said Laurent Bigorgne, director of the Institut Montaigne. “Growth is not at the level we expected and the budget is a difficult equation to balance,” he said, adding “there is also the challenge of the European elections next year: picking candidates and defending the European project in a difficult context. And we’ve not yet started on the reform of the French state”.

The most pressing issue in the days ahead is to find a successor for Mr Hulot. The new appointment will need to show that, contrary to Mr Hulot’s criticism, France is serious about ecological issues. And it comes at a critical moment for France’s energy policy, which the environment minister oversees.

The French government is preparing to unveil a multiyear energy programme in the autumn, which will set out its priorities for the next ten years, and the road map for a belated shift away from nuclear towards renewables. France has a revised target of cutting the proportion of energy generated from nuclear to 50 per cent by 2035.

Mr Hulot’s vehemently anti-nuclear stance clashed with the more nuanced view of the government. Speaking on Thursday, Bruno Le Maire, French finance minister, said: “I think we can perfectly remember that nuclear power is an asset for France and accelerate the development of renewable energies in France.” “

We think France has no real choice but to extend the lifetime of the nuclear fleet — the alternative would be a cliff edge in power supply in the 2020s,” said Sam Arie, utilities analyst at UBS.

“Even with nuclear life extensions, there could still be a risk — so we think France also needs to catch up its very slow start on renewables. Perhaps we could see a national investment plan for wind and solar, a “Macron plan” to mirror the 1974 “Messmer plan” which led to the construction of today’s nuclear fleet?

” Despite these challenges, investors remain optimistic on France. “The real achievement of Macron’s tenure so far is enforcing changes that were previously unimaginable,” wrote Pierre-Henri Flamand, chief investment officer of hedge fund manager Man GLG in a note to clients on Tuesday. “The opposition on both sides of the political divide is weak and fragmented, buying Macron time to implement the changes he needs to make.”